FT4232H datasheet(21/45 Pages) FTDI

Part #	FT4232H

Description	Quad High Speed USB to Multipurpose UART/MPSSE IC

PDF	45 Pages

Scroll/Zoom	100%

Manufacturer	FTDI [Future Technology Devices International Ltd.]

Direct Link	http://www.ftdichip.com

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21 / 45 page

Document No.: FT_000060

FT4232H QUAD HIGH SPEED USB TO MULTIPURPOSE UART/MPSSE IC

Datasheet Version 2.2

Clearance No.: FTDI#78

4.4.1 MPSSE Adaptive Clocking

Adaptive clocking is a new MPSSE feature added to the FT24232H MPSSE engine.

The mode is effectively handshaking the CLK signal with a return clock RTCK. This is a technique used by

ARM processors.

The FT4232H will assert the CLK line and wait for the RTCK to be returned from the target device to

GPIOL3 line before changing the TDO (data out line).

FT4232H

ARM CPU

RTCK

TCK

TDO

GPIOL3

Figure 4.5 Adaptive Clocking Interconnect

TDO

TCK

RTCK

TDO changes on falling

edge of TCK

Figure 4.6: Adaptive Clocking waveform.

Adaptive clocking is not enabled by default.

See: AN_108 Command Processor for MPSSE and MCU Host Bus Emulation Modes.

FT4232H Datasheet(PDF) 21 Page - Future Technology Devices International Ltd.